Besides @jonbaas’s answer, I would recommend that you don’t force your buyer to leave you a 5-star review, as that is not allowed. If your buyer wants to give you a rating, they will do it.

However, some buyers will not review their orders. In that case, you could ask your buyer to rate you if they liked your work, just don’t ask for a specific rating (don’t ask them to give you 5 stars). Just tell them to rate your order if they liked your work or found it useful/helpful.

Asking for specified reviews or suggestive requests are frowned up not only inside Fiverr, but anywhere in the outside world as well.
It a an improper work etiquette, and should be avoided at all costs.
Rest assured, if you are good at what you do, you need not bother about the reviews. They’ll keep on pouring all by themselves.